Create ZUGFeRD / Factur-X Invoice

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate this is a write operation (readOnlyHint=false). The description adds that the API performs authoritative validation and returns generation metadata, which is useful context. However, openWorldHint=true is not addressed, and no side effects (e.g., external calls, persistence) are disclosed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences with zero filler. It front-loads the main purpose and then adds a valuable note about validation. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the complex nested schema and no output schema, the description is far too incomplete. It does not explain the return metadata structure, prerequisites, common use cases, or how the many fields interrelate. The sparse description leaves the agent to infer critical details from the schema alone.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema coverage is only 40% and the description provides no parameter-level detail. It does not explain the required 'data' object, how to structure nested fields, or clarify any of the poorly documented parameters. The description adds no meaning beyond the schema's existing field descriptions.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool generates a ZUGFeRD/Factur-X document package with specific components (visual PDF, EN16931 CII XML, hybrid PDF). This distinctly separates it from sibling tools like pop_create_sdi_invoice or pop_create_peppol_invoice.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for ZUGFeRD/Factur-X invoices but gives no explicit guidance on when to choose this over alternatives, nor any exclusions or context about regional/regulatory applicability. It lacks a 'when to use vs. other tools' statement.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.